FR2915872A1 - INSTALLATION FOR THE INJECTION OF WATER VAPOR IN A HUMAN OR ANIMAL BLOOD VESSEL - Google Patents

Abstract

Apparatus intended for the injection of pulsed steam into a human or animal vessel comprising an injection unit sending pulses of cold water into a handpiece, a handpiece temporarily attached to an injection unit within which there is a metal tube, of external diameter between 200 μm and 1,000 μm and internal diameter between 100 μm and 500 μm, the metal tube having its distal end coiled to form a spiral, the tube being sheathed with a material of resistivity such that only the spiral heats to a temperature transforming water from the liquid phase into the vapor phase, a means of distributing the steam into the vessel intended to be connected in a reversible manner to the distal end of the handpiece.

Description

INSTALLATION FOR INJECTING WATER VAPOR IN A VESSEL

HUMAN OR ANIMAL BLOOD

  The invention relates to a new device for the treatment of venous or arteriovenous pathologies, in particular varicose veins, hemorrhoids and arteriovenous shunts or other vascular malformations by injection of water vapor endoluminally.

  More precisely, the subject of the invention is an installation intended for pulsed injection of steam into a human or animal vein.

  US 2003/0109869 A1 discloses a method of treating varicose veins. The proposed system consists in injecting steam directly into the vein, in order to destroy the varicose veins by heating the collagen present on their wall. In practice, the transformation of water into steam is carried out directly into the vein, the water being heated at the distal end of a catheter by an electric arc formed by means of a spirally wound electrode.

  This installation has several disadvantages. The first relates to the high energy power for converting water into steam by the electric arc. In addition and above all, the catheters constitute consumable products and therefore not reusable from one patient to another, which, taking into account the technical complexity of this type of catheter, considerably increases the cost of the material and therefore of the patient. intervention. In order to reduce this cost, it would be advantageous to transform the water into steam no longer at the level of the consumable catheter, but further upstream, that is to say at the level of the means for supplying the liquid to the catheter. introduced into the vein.

  In another field relating to that of ablations or tissue cauterizations, WO 02/069821 discloses an apparatus in which the transformation of water into steam is performed in a handpiece outside the body. In the proposed system, the handpiece houses a tube having two electrodes connected to a radio frequency generator, the liquid ensuring the flow of current between the two electrodes. The disadvantage of this system is that it has a tube with no differential heating, which means that the tube is heated along its entire length. Therefore, not only is there a loss of heat, but more importantly, the user, given the heating temperatures, can be hampered when gripping the handpiece and therefore the intervention. This phenomenon is reinforced because of the steady state of production and vapor transfer which causes warm-ups not only for the user but also and especially for the patient.

  Finally, the Applicant's document WO 2006/108974 describes an installation for injecting pulsed steam not into a vein, but directly into the tissues, in particular for the treatment of tumors. In the proposed device, the heating is not performed in the handpiece, that is to say outside the body, but directly in the catheter in contact with the tissue. Unlike the previous document, the heating is here differential, that is to say that the transformation of water into steam is performed exclusively at the distal end of the tube incorporated in the body. If this installation allows effective treatment of tumors, it has the major disadvantage of remaining relatively expensive, insofar as the miniaturization of the heating system in the tubes in contact with the body, that is to say say consumables, has a very high cost.

  In other words, the problem to be solved by the invention is to develop an installation for the treatment, in particular varicose veins and hemorrhoids by endoluminal vapor injection, including the heating system and therefore the transformation of the water vapor is deported outside the body.

  In other words, the object of the invention is to develop a device in which the change of state of the liquid is performed in the handpiece respecting the two constraints that are the comfort of grip by the room surgeon. hand and effective heating of the vessel and in particular the vein at the level of the varicose vein or hemorrhoid to be treated without burning for the patient at the level of the skin.

  To do this, the Applicant has managed to develop a handpiece in which the transformation of water into steam is exclusively performed at the distal end of said handpiece in an area not in contact with the hand of the surgeon, all the elements of the installation being developed and arranged to allow the administration of steam in the pulsed regime, to the distal end of the device, that is to say at the level of the vessels to be treated, the pulsed regime for the rapid transfer of the 3 calories of the handpiece at the end of the diffusion means so as to provide local calories as quickly as possible to reduce undesirable heat losses.

  The subject of the invention is therefore an installation intended for the pulsed injection of water vapor into a human or animal vessel, comprising: a unit for injecting cold water under pulsed conditions into a handpiece; a handpiece temporarily secured to the injection unit in which is arranged a metal tube in which the cold water is transformed into steam, - a steam diffusion means in the vessel to be connected in a manner reversible at the distal end of the handpiece, characterized in that the metal tube: has an external diameter of between 200 m and 1000 m, preferably of the order of 800 m and an internal diameter of between 100 m and 500 m, advantageously of the order of 250 m, has a distal end wound on itself to form a spiral, and in that the two ends of the tube are connected to an electrical source, the portion of tube included in between its proximal end and the proximal end of the spiral being sheathed with a material, advantageously a copper braid, having a resistivity such that only the spiral is able to heat to a temperature permitting the passage of water from the phase liquid to the vapor phase.

  In other words, the Applicant has managed to develop a system in which the differential heating is made possible at the handpiece, that is to say in a semi-consumable room, decreasing thus the cost of the installation. In practice, the semi-consumable can indeed be reusable for twenty interventions. In addition, the specific conformation of the microtube in which water circulates at the handpiece maintains the vapor state of the distal end of the handpiece at the distal end of the diffusion means.

  In practice and according to another characteristic, the spiral is formed around a portion of a metal tube of low electrical resistance, in practice less than 0.5 ohm, to ensure the return of the electric current without heating, of which: - l the proximal end in contact with the spiral is sheathed with an electrically and thermally insulating material, the conductive portion of the tube being connected to the current-carrying electrical source; the distal end is free of electrically and thermally insulating sheath and is contact with the distal end of the tube traversed by the liquid.

  Furthermore, given the diameter of the tube traversed by the liquid and the size of the handpiece which must be easily manipulated by the surgeon, the length of the wound tube to form a spiral is between 10 and 30 cms, preferably from the order of 20 cms.

  To avoid the risk of a short-circuit and to minimize the heating temperature at the distal end of the handpiece, the distal end of the tube in the zone in which the spiral is arranged is sheathed by an insulating layer. thermally and electrically.

  Advantageously, to further improve the thermal insulation, the distal end of the handpiece is formed at the region in which the spiral is arranged, a thermally insulating material and in particular silicone.

  To allow the surgeon to have a certain freedom of movement, the handpiece is advantageously irreversibly connected to an extension connecting the cold water injection unit. In this configuration, the installation then comprises non-consumable equipment (injection unit), semi-consumable elements (handpiece and extension) and consumable elements (diffusion means).

  With regard to the latter, it can present three distinct forms.

  In the first two cases, the diffusion means is in the form of a metal tube of inner and outer diameter advantageously lower than those of the tube located in the handpiece, between 100 and 200 m, advantageously 150 m for the inner diameter and between 250 and 500 m, advantageously 350 m for the outer diameter, thus allowing it to confer a certain flexibility and reduce heat exchange.

  In a first embodiment, the distal end of the microtube is closed, advantageously via a rounded stainless steel part attached to said end, the tube having near its distal end, or on the tube 5 itself , or on the insert, at least one through hole. To avoid necrosis of the vessel wall, the tube is covered over its entire surface, but with the exception of the possible through orifice, with a layer of a thermally insulating material such as in particular PTFE, PEEK, polyimide or silicone, preferably PTFE.

  In another embodiment, the microtube is sheathed with a thermally insulating material, the sheath not being fixed but mobile along the microtube. In this case, the length of the insulating sheath is greater than the length of the microtube, which makes it possible, because of the flexibility of the sheath, to avoid perforating the vessel with the microtube at the time of introduction of the microtube. the latter in said vessel. In practice, the microtube has an orifice positioned at its end end ensuring the delivery of vapor pulses.

  In these two embodiments, the microtube has throughout its length a marking, in practice every centimeter, to indicate to the operator the remaining microtube length in the vessel as the withdrawal thereof .

  In another embodiment, the diffusion means is not in the form of a microtube, but in the form of a needle, the needle being covered on at least its surface in contact with the vessel, a thermally insulating material, such as for example PTFE. In practice, the needle has three portions obtained by decreasing external section grinding of the proximal end towards the distal end, respectively: a proximal portion with an external diameter of between 1.4 and 1.9 mm; median external diameter between 1 and 1.3 mm, - a distal portion of external diameter between 0.5 and 0.8 mm, the internal diameter of the needle being constant and between 0.1 and 0.25 mm, advantageously equal to 0.15 mm.

  Of course, broadcast medium and handpiece are connected by any suitable means known to those skilled in the art.

  Regarding the injection unit, it is similar to the unit described in WO 2006/108974. More particularly, the injection unit is in the form of a chamber containing the water to be injected and in which a hydraulic jack controlled by an electric, pneumatic, piezoelectric or mechanical jack, whose triggering and / or force and / or the speed of movement are determined as a function of the rate, volume and the desired injection pressure of the substance in the handpiece by the hydraulic cylinder. The injection unit may also be associated with a cold water storage unit.

  The subject of the invention is also a method for treating venous or arteriovenous pathologies, in particular varicose veins, hemorrhoids and arteriovenous shunts, and more generally vascular malformations by injecting vapor pulses into the vessels (veins and / or arteries) endoluminally using the previously described device. The advantage of the installation is to allow the homogeneous diffusion of steam over several centimeters (in practice 4 to 5 cm) in the vessels, which avoids any risk of carbonization or perforation of the wall as it could exist with the installation described previously in the document US 2003/0109869 or in the other existing thermal techniques, generating a point heat.

  The invention and the advantages resulting therefrom will emerge more clearly from the following exemplary embodiments in support of the appended figures.

  Figure 1 is a schematic representation of the installation of the invention. Figure 2 is a sectional representation of the handpiece and the extension of the invention.

  Figure 3 is a detail representation of the distal end of the handpiece, object of Figure 2. Figure 4 is a schematic illustration of the diffusion means in a first embodiment. Figures 5 and 6 are schematic representations of the diffusion means in a second embodiment.

  Fig. 7 is a schematic representation of the diffusion means in a third embodiment.

  Figure 1 shows the installation of the invention schematically. As shown in this figure, the installation comprises three essential elements that are: - a cold water injection unit (1) in the form of pulses, - a set extended handpiece (2) at the distal end of which water is transformed into vapor, - a means of diffusion of water vapor into the vein in the form of a catheter or microtube (3).

  In practice, the injection unit is further associated with a pocket (4) for storing water.

  The generator of cold water pulses does not need to be described in detail and is similar to that illustrated in the aforementioned application WO 2006/108974 A1. In practice, the injection unit is in the form of a chamber containing a substance to be injected, in this case cold water, in which a hydraulic cylinder of small diameter, of the order of 3 to 5 mm, is controlled by an electric, pneumatic, piezoelectric or mechanical cylinder of greater diameter, of the order of 50 to 80 mm, the release and / or the stroke and / or the force and / or the speed of displacement are determined according to the rhythm, the volume and the injection pressure desired, of the substance in the extension-handpiece assembly by the hydraulic cylinder.

  To prevent the return of water into the injection unit after injection of said water into the hand-extension unit assembly, the injection unit contains two check valves (not shown). As already stated, the pressure at which the substance is injected depends on the speed of movement and the force of the cylinders, for example pneumatic, which are also programmed.

  The means for diffusing water vapor into the vessel is separated from the injection unit by an extension-handpiece assembly (2) shown in FIG. 2. Specifically, the illustrated assembly comprises a hand (5), an extension (6), and a connection means (7) to the injection unit in the form of a thread. The handpiece (5) and the extension (6) have a generally tubular shape. The connection between the extension and the handpiece on the one hand, and the screw thread (7) on the other hand, is obtained by the 8 placing of the intermediate pieces (8, 9). The parts (8, 9) are mounted irreversibly. The extension-handpiece assembly thus constitutes a semiconsommable element. In practice, the extension can reach 1.5 to 5 m in length while the handpiece has a size of about 10 to 20 cms. According to the invention, the extender-handpiece assembly is traversed by a tube (10) in which the liquid circulates. The tube is made of stainless steel and has an internal diameter of 250 m and an external diameter of 800 m. The material constituting the tube has a resistivity equal to 72 S2 / cm. As shown in FIG. 3, the distal end of the tube (10) is wound around a portion of stainless steel tube (11) of low resistance to form a spiral (12), in practice of 20 cms linear. The portion of stainless steel tube (11) in contact with the spiral (12) is covered with an electrically and thermally insulating sheath (13). The proximal end (14) of the tube portion (11) is in contact with an electrical conductor (15) connected to the positive pole of a not shown electrical source. The distal end (16) of the tube portion (11) has an opening (17) for passing the distal end (18) of the spiral (12) so as to be in contact with the conductor electric formed by the portion of stainless steel tube (11) of low resistance, in practice less than 0.5 S2. As shown in Figure 3, the distal end of the tube portion (11) is devoid of insulating sheath thus allowing the flow of the stainless steel tube (11) in the spiral (12). To allow heating in the single spiral portion of the tube (10) and not its rectilinear portion between its proximal end (19) at the outlet of the injection unit and the proximal end (20) of the spiral (12), the rectilinear portion is provided with a sheath in the form of a copper braid of low resistivity. The screw thread (7) integrates the hydraulic connection which at the same time acts as an electric ground (27). In other words, the current flows in the electrical conductor (15), then in the spiral (12) to return through the tube (10) to the mass (27). According to another characteristic, the spiral (12) is provided with an electrically and thermally insulating sheath (21). Furthermore, the distal end of the handpiece is provided with a silicone part (22) to prevent overheating of the handpiece. Figure 4 is a representation of a broadcast means in a first embodiment. In this configuration, the diffusion means is in the form of a microtube (23) of internal diameter equal to 150 m and external diameter equal to 350 m. This microtube (23) is connected to the distal end of the handpiece by any suitable means defined schematically by the reference 24. According to an essential characteristic, the distal end of the microtube is closed by a stainless steel part (25) reported fitted. a through hole (26) allowing the passage of steam. In practice, with the exception of the insert, the microtube is covered with a thermally insulating substance of the PTFE and / or PEEK type (28). The microtube also has near its proximal end, a gripping means (29) facilitating the establishment by the surgeon of the microtube in the vessel.

  In the embodiments of Figures 5 and 6, the PTFE sheath (28), arranged around the microtube (23) is not fixed, but mobile. In this case, the microtube is not closed and thus provided with a terminal orifice (30).

  Figure 5 shows the scattering means at the time of placement, while Figure 6 shows the same scattering means at the time of processing.

  As shown in these figures, the sheath or PTFE tube (28) has a length greater than that of the microtube so as to avoid any perforation in the area to be treated by said microtube at the time of its introduction. In the treatment position, the PTFE tube is withdrawn back through the part (29) left outside the body. Of course, the connection between the proximal end of the microtube and the distal end of the handpiece is carried out by any known means, shown schematically by the reference 24.

  Fig. 7 is a representation of the diffusion means in a third embodiment. In this case, the microtube is replaced by a needle (31) of continuous internal diameter equal to 0.15 mm having three distinct portions obtained by grinding, respectively: a proximal portion (32) of external diameter equal to 1.6 mm a median portion (33) of external diameter equal to 1.2 mm, and a distal end (34) of external diameter equal to 0.7 mm. The part of the needle intended to be inserted into the vessel is coated with a Teflon sheath or silicone deposit not shown. Moreover, during storage, the needle is surrounded by a protective tube (35) of a length substantially greater than that of the needle.

  As already stated, the apparatus of the invention is intended for the treatment of venous or arteriovenous pathologies and more particularly for the treatment of varicose veins or hemorrhoids. In practice, the generator is designed to deliver water pulses of volume between 50 and 100 l, preferably 70 l, to convey between 30 and 100 J, preferably of the order of 50 J.

  The method of treatment will now be described in detail in connection with varicose veins and the implementation of a means of diffusion in the form of a microtube (FIGS. 4 to 6). The diagnostic evaluation of the pathology by Doppler ultrasound is carried out beforehand. The vein to be treated is then marked by marking the path of the vein and the introduction orifice of the microtube delivering the vapor with the skin.

  Depending on the diameter of the vessel to be treated, the number of pulses to be delivered per linear centimeter of vessel to be treated is then determined. For example, for a vein 12 mm in diameter, two pulses are sent, each 70 l of water, each pulse carrying an energy of 50 J.

  The treatment can then begin either under local anesthesia or under general anesthesia depending on the wishes of the patient.

  The method of treatment first involves puncturing the vessel, and more particularly the vein to be treated, by means of a needle positioned in a small catheter about 5 cm in length, the surface of which is teflonated, the needle being removed after placement of the catheter on the surface of the skin. The microtube is then introduced into the catheter in one of the configurations of FIGS. 4 or 5, 6 above, until the distal end of the microtube reaches the end of the vein to be treated. The generator then sends the pulses of cold water in the handpiece, which transforms these pulses into steam at a temperature of about 200 C, the vapor is then conveyed by the microtube to its distal end.

  Thanks to the marking made on the surface of the microtube, the operator gradually withdraws said microtube at the rate of 1 to several pulses per centimeter, depending on the diameter of the vessel. According to an essential characteristic, it is not necessary that the withdrawal be continuous and regular, so that the installation does not require additional equipment to automate the withdrawal.

  The facility can also be applied to the treatment of hemorrhoids.

  In this case, the lesions are visualized by means of an anoscope. Forceps are then placed at the base of the hemorrhoid to interrupt blood flow and limit heat transfer at the anal wall. A thin needle of the type previously described (FIG. 7) is then inserted, surrounded by an insulating material to protect the mucosa against burns, all under visual control. The heating is then started and 1 to 3 pulses of steam are emitted. The needle is then removed, the forceps opened and removed. During the treatment, air or liquid cooling can be carried out to protect the surrounding structures. The anal mucosa can also be protected by an optionally anesthetic gel.

  The invention and the advantages thereof will be apparent from the foregoing description. In particular, the development of an installation capable of injecting steam pulses directly into a vein and where the heating is carried out in semi-consumables and not consumables.

  In addition, one of the interesting points of the technique developed by the Applicant is to have a uniform temperature over 5 to 6 cm of length of vein, which allows to remove in successive steps, the diffusion means. On the contrary, other technologies, such as RF or laser provide a point heat with the risk of necrosis punctually the entire wall of the vein.

  Another advantage of the technique is to be able to treat a vein with either blood or blood, while the laser treats the vein with its blood and the RF treats the vein emptied of its blood.

Claims (3)

  1 / Installation intended for the pulsed injection of water vapor into a human or animal vessel comprising: - a cold-water injection unit (1) pulsed in a handpiece (5), a handpiece (5) temporarily secured to the injection unit (1) in which is arranged a metal tube (10) in which the cold water is transformed into vapor, - a steam diffusion means in the vessel intended to be reversibly connected to the distal end of the handpiece, characterized in that the metal tube (10): - has an external diameter of between 200 m and 1000 m and an internal diameter of between 100 m and 500 m, - has a distal end wound on itself to form a spiral (12), and in that both ends of the tube are connected to an electrical source (27, 15), the tube portion between its proximal end (19) and the proximal end (20) ) of the spiral (12) being sheathed with a material having a resistivity such that only the spiral heats to a temperature allowing the passage of water from the liquid phase to the vapor phase. 2 / Apparatus according to claim 1, characterized in that the spiral (12) is formed around a portion of a metal tube (11) of low electrical resistance of which: - the proximal end 14) in contact with the spiral (12) is sheathed with an electrically and thermally insulating material (13), the conductive portion of the tube being connected to the current-carrying electrical source, - the distal end (16) is free of electrically and thermally insulating sheath and is in contact with the distal end of the tube (10) traversed by the liquid. 3 / Apparatus according to one of the preceding claims, characterized in that the length of rolled tube to form a spiral (12) is between 10 and 30 cms, preferably close to 20 cms.4 / Installation according to one of claims previous, characterized in that the distal end of the tube (10) in the region in which the spiral (12) is arranged is sheathed by an insulating layer (21) thermally and electrically. 5 / Apparatus according to one of the preceding claims, characterized in that the distal end of the handpiece is formed, at the region in which the spiral is arranged, a thermally insulating material, in particular silicone (22). 6 / Apparatus according to one of the preceding claims, characterized in that the handpiece (5) is rigid and irreversibly connected to a flexible extension (9). 7 / Apparatus according to one of the preceding claims, characterized in that the diffusion means is in the form of a metal tube (23) of internal diameter of between 100 and 200 m and external between 250 and 500 m, whose distal end is closed by means of a steel insert (25) provided with at least one through orifice (26), the tube being further covered, over its entire surface, with a layer of a thermally insulating material (28). 8 / Apparatus according to one of claims 1 to 6, characterized in that the diffusion means is in the form of a metal tube (23) of internal diameter of between 100 and 200 m and external between 250 and 500 m, whose distal end is open (30), the tube being covered with an insulating sheath (28) thermally movable along the tube and of larger size than the metal tube. 9 / Apparatus according to one of claims 1 to 6, characterized in that the diffusion means is in the form of a needle (31) covered on at least the surface intended to be in contact with a thermally insulating material, the needle having three portions obtained by rectifying the external section decreasing from the proximal end to the distal end, respectively: a proximal portion (32) having an internal diameter of between 1.4 and 1.9 mm; median (33) with an internal diameter of between 1 and 1.3 mm, - a distal portion (34) with an internal diameter of between 0.5 and 0.8 mm, the internal diameter of the needle being constant and between 0.1 and 0.25 mm, advantageously equal to 0.15 mm. 10 / Installation according to one of the preceding claims, characterized in that the injection unit (1) is in the form of a chamber containing the water to inject and in which a hydraulic cylinder controlled by an electric, pneumatic, piezoelectric or mechanical actuator, whose release and / or the force and / or the speed of displacement are determined according to the rhythm, the volume and the desired injection pressure of the substance in the room hand held by the hydraulic cylinder.